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Gallatin County

North of Manhattan, the Horseshoe Hills rise gently from the valley floor. The rocks here include the Meagher Shale, laid down in a shallow Cambrian sea over five hundred million years ago. Trapped within the delicate, paper-thin layers of shale are the fossilized remains of trilobites, specifically the rare Bathyuriscus formosus.

Visitor Access

Land ownership in the Horseshoe Hills is a tight patchwork of private ranches and state trust lands. Collecting fossils on private land requires explicit permission. On state trust lands, a recreational use license is required, and the collection of significant fossils is heavily restricted. This is an area where precise navigation and landowner permission are absolute requirements.